Heart valve chord cutter

ABSTRACT

A medical device and method for percutaneously treating a heart valve. In one embodiment, the medical device includes a catheter having a proximal portion, a distal portion, and a notch formed near the distal portion. A cutting element may be disposed within the distal portion and is moveable across the notch to slice through a heart chord.

The present application is a divisional of co-pending U.S. applicationSer. No. 10/295,383, filed Nov. 15, 2002.

TECHNICAL FIELD

The disclosure, in one embodiment, relates generally to the treatment ofheart related diseases, and more particularly, in one embodiment, to thetreatment of defective heart valves.

BACKGROUND

FIG. 1A illustrates a heart 10 with a partial internal view and arrowsindicating the direction of blood flow within the heart. Four valves inthe heart 10 direct the flow of blood within the left and right sides ofthe heart. The four valves include a mitral valve 20, an aortic valve18, a tricuspid valve 60, and a pulmonary valve 62 as illustrated inFIG. 1A. The mitral valve 20 is located between the left atrium 12 andthe left ventricle 14. The aortic valve 18 is located between the leftventricle 14 and the aorta 16. These two valves direct oxygenated bloodcoming from the lungs, through the left side of the heart, into theaorta 16 for distribution to the body. The tricuspid valve 60 is locatedbetween the right atrium 22 and the right ventricle 24. The pulmonaryvalve 62 is located between the right ventricle 24 and the pulmonaryartery 26. These two valves direct de-oxygenated blood coming from thebody, through the right side of the heart, into the pulmonary artery 26for distribution to the lungs, where it again becomes re-oxygenated anddistributed to the mitral valve 20 and the aortic valve 18.

The heart valves are complex structures. Each valve has “leaflets” thatopen and close to regulate the direction of blood flow. The mitral valve20 has two leaflets and the tricuspid valve 60 has three leaflets. Theaortic 18 and pulmonary 62 valves have leaflets that are referred to as“cusps,” because of their half-moon like shapes. The aortic 18 andpulmonary 62 valves each have three cusps.

During diastole, the leaflets of the mitral valve 20 open, allowingblood to flow from the left atrium 12 to fill the left ventricle 14.During systole, the left ventricle 14 contracts, the mitral valve 20closes (i.e., the leaflets of the mitral valve 20 re-approximate), andthe aortic valve 18 opens allowing oxygenated blood to be pumped fromthe left ventricle 14 into the aorta 16. A properly functioning mitralvalve 20 allows blood to flow into the left ventricle and preventsleakage or regurgitation of blood back into the left atrium (andsubsequently back into the lungs). The aortic valve 18 allows blood toflow into the aorta 16 and prevents leakage (or regurgitation) of bloodback into the left ventricle 14. The tricuspid valve 60 functionssimilarly to the mitral valve 20 to allow deoxygenated blood to flowinto the right ventricle 24. The pulmonary valve 62 functions in thesame manner as the aortic valve 18 in response to relaxation andcontraction of the right ventricle 24 (i.e., to move de-oxygenated bloodinto the pulmonary artery 26 and subsequently to the lungs forre-oxygenation).

During relaxation and expansion of the ventricles 14, 24, (i.e.,diastole), the mitral 20 and tricuspid 60 valves open, while the aortic18 and pulmonary 62 valves close. When the ventricles 14, 24, contract(i.e., systole), the mitral 20 and tricuspid 60 valves close and theaortic 18 and pulmonary 62 valves open. In this manner, blood ispropelled through both sides of the heart (as indicated by the arrows ofFIG. 1A). The chordae tendineae are tendons linking the papillarymuscles to the tricuspid valve in the right ventricle and the mitralvalve in the left ventricle. As the papillary muscles contract andrelax, the chordae tendineae transmit the resulting increase anddecrease in tension to the respective valves, helping them to open andclose properly. The chordae tendineae are string-like in appearance andare sometimes referred to as “heart strings.” FIG. 1B illustrates anenlarged view of the mitral valve region of the heart with leaflets 25,26 forming a coapted surface to prevent backflow of blood into the rightatrium 12 from the left ventricle 14. Leaflet 26 is tethered by chordae30, 31 to papillary muscle 27, and leaflet 25 is tethered by chordae 32,33, and 34.

Regurgitation is a condition in which leaflets of a heart valve do notclose completely, resulting in the backflow of blood. For instance, in acondition typically referred to as mitral valve regurgitation, theleaflets of the mitral valve do not close completely during systole andblood leaks back into the left atrium. Studies have shown that oneeffect of mitral valve regurgitation is the distortion or displacementof the left ventricle, as well as the papillary muscles to which themitral valve leaflets are attached by the chordae. Displacement of thepapillary muscles away from the mitral valve annulus tethers theleaflets into the left ventricle, thereby preventing the leaflets fromclosing effectively. FIG. 1C illustrates an enlarged view of the heartas shown by FIG. 1B, but with papillary muscle 27 displaced further downin left ventricle 14. Because of the displacement of papillary muscle27, chordae 34 pulls on leaflet 25 eliminating the coapting surfacebetween the leaflets. This allows oxygenated blood to flow back into theleft atrium 12, and the heart is then forced to work harder to pumpenough oxygenated blood to the body. This may lead to heart damage overa period of time. Regurgitation is common, occurring in approximately 7%of the population. Mitral valve regurgitation may be caused by a numberof conditions, including genetic defects, infections, coronary arterydisease (CAD), myocardial infarction (MI), or congestive heart failure(CHF).

Faulty or defective valves may be treated with various surgicalprocedures. Annuloplasty, for example, reduces the annular size of themitral valve by placing a synthetic ring around the rim of the mitralvalve. These types of procedures are typically major, invasive surgicalprocedures that may require opening the chest by sternotomy, makingincisions in the chest wall, heart-lung bypass and suspending thebeating of the heart. These invasive procedures subject patients to atremendous amount of pain and discomfort and require lengthy recoveryand/or hospitalization periods. Patients with congestive heart failuremay not be able to tolerate the surgical procedures, leaving them withlittle or no alternative to treat their defective heart valves.Moreover, reducing the annular size alone may still leave the patientwith regurgitation symptoms because the mitral valve leaflet may stillbe tethered by chordae to the displaced papillary muscles andventricular walls.

SUMMARY OF THE DISCLOSURE

A medical device and method for percutaneously treating a heart valve isdescribed. In one embodiment, the medical device includes a catheterhaving a proximal portion, a distal portion, and a notch formed near thedistal portion. A cutting element may be disposed within the distalportion and is moveable across the notch to slice through a heart chord.

Additional embodiments, features and advantages of the medical devicewill be apparent from the accompanying drawings, and from the detaileddescription that follows below.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is illustrated by way of example, and notlimitation, in the figures of the accompanying drawings in which:

FIG. 1A illustrates a heart.

FIG. 1B illustrates an enlarged view of the mitral valve region of aheart.

FIG. 1C illustrates another enlarged view of the mitral valve region ofthe heart.

FIG. 2 illustrates a side view of a medical device that may be used tocut a heart chord percutaneously.

FIG. 2A illustrates a cross-sectional view of the device illustrated inFIG. 2.

FIG. 2B illustrates a cross-sectional view of the device illustrated inFIG. 2.

FIG. 2C illustrates a cross-sectional view of the device illustrated inFIG. 2.

FIGS. 3A-3D illustrate one exemplary embodiment of the mechanical actionof a cutting element disposed within a medical device.

FIGS. 4A-4B illustrate one embodiment of steering tendons disposedwithin a catheter to provide steering capabilities.

FIGS. 5A-5D illustrate alternative embodiments of steering tendonsdisposed within a catheter.

FIGS. 6A-6C illustrate side views of alternative embodiments for acutting element that may be disposed within a medical device.

FIGS. 7A-7C illustrate side views of alternative embodiments for notchdesigns that may be formed within a distal portion of a medical device.

FIGS. 8A-8D illustrate cross sectional views of alternative embodimentsfor a groove that may be formed within a medical device.

FIGS. 9A-9B illustrate an alternative embodiment for preventing rotationof a cutting element disposed within a catheter.

FIGS. 10A-10D illustrate one exemplary method for cutting a mitral valvechordae tendineae percutaneously.

FIGS. 11A-11B illustrate one embodiment of a medical device to treat aheart valve.

FIGS. 12A-12B illustrate one embodiment of performing a combination ofpercutaneous procedures.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forthsuch as examples of specific materials or components in order to providea thorough understanding of the present disclosure. It will be apparent,however, to one skilled in the art that these specific details need notbe employed to practice the disclosure. In other instances, well knowncomponents or methods have not been described in detail in order toavoid unnecessarily obscuring the present disclosure. Embodiments of amedical device discussed below are described with respect to thetreatment of a mitral valve. It may be appreciated, however, that otherheart valves or body tissue may be treated, and embodiments of themedical device are not limited in their applicability to treating themitral valve.

Embodiments of a medical device and methods for treating the mitralvalve percutaneously are described. A medical device, in one embodiment,may be used to treat mitral valve regurgitation or prolapse by severinga mitral valve chordae tendineae that prevents the proper closing of amitral valve leaflet during systole. In one embodiment, the medicaldevice includes an elongated catheter having a proximal portion and adistal portion. The distal portion may have a notch or an aperturewindow appropriately sized for positioning a cardiac tissue or heartvalve chord (e.g., a chordae tendineae tethered to a mitral valveleaflet) therein. A cutting element may be disposed within a lumenformed within the elongated catheter and positioned near the distalportion. The cutting element may be moved or actuated across the notchto slice through the cardiac tissue (e.g., one or more selected chordae)positioned within the notch. In one embodiment, the cutting element maybe a sharp blade. In another embodiment, the blade may be coupled to acontrol mechanism disposed near a proximal portion of the catheter andoutside of a patient. The control mechanism may be handled by anoperator to move the blade back and forth across the notch. In oneembodiment, the blade may slice through a cardiac tissue by a retractingaction that moves the blade from a first position distal to the notch toa second position proximal to the notch. In an alternative embodiment, acutting element may be disposed internally in a catheter and be movedthrough a slot in the catheter wall to a position outside of thecatheter, thereby allowing the cutting element to cut one or moreselected chordae. In this alternative embodiment, the catheter does notinclude a notch.

In one method for treating mitral valve prolapse caused by an elongatedchordae tendineae, the chordae may be severed with a medical device thatis percutaneously advanced to the target chordae. The medical device mayinclude an elongated catheter having a proximal portion and a distalportion, with a notch formed near the distal portion for securing themedical device to the chordae. A cutting element may be disposed withinthe catheter near the distal portion, and moveable across the notch toslice through the chordae. In one embodiment, the distal portion of theelongated catheter may be inserted into a patient through, for example,the femoral artery, down the aortic valve, and into the left ventricle.The medical device may also include a control mechanism disposed nearthe proximal portion of the catheter that has one or more handles forsteering the distal portion of the catheter for advancement into theleft ventricle. In one embodiment, one or more steering tendons mayextend from the control mechanism to the distal portion of the catheterto provide steerability to the catheter. The control mechanism may alsoinclude a separate handle coupled to a wire that extends from the handleand coupled to the cutting element. The handle may by used to cause aforward or reverse movement of the cutting element across the notch toslice through the chordae. In one embodiment, the cutting element, whichmay be a blade, may be retracted from a first position distal to thenotch to a second position proximal to the notch using a handle disposedon a control mechanism. This exemplary embodiment provides an advantageof percutaneously treating mitral valve prolapse without the need forinvasive surgical procedures.

Referring now to FIGS. 11A-11B, side and top views of one embodiment ofa medical device to treat a heart valve are illustrated. Medical device1100, in one embodiment, may be used to cut one or more heart chords(e.g., a mitral valve chordae) percutaneously. FIG. 11A shows a sideview of medical device 1100 having a proximal portion 1110, an elongatedcatheter portion 1105, and a distal portion 1120. Elongated catheterportion 1105 is not drawn to scale and may be of an appropriate lengthto reach a target region within a patient. Elongated catheter may besubstantially tubular and may be appropriately sized to fit withinlumens of a patient (e.g., arteries and vessels). Proximal portion 1110includes a control mechanism 1112 having one or more handles or controlelements (e.g., handle 1114). Distal portion 1120 includes a notch 1122formed into the catheter body. A top view of medical device 1100, asillustrated by FIG. 11B, shows notch 1122 having a width substantiallysimilar to a diameter of catheter 1105. The opening formed by notch 1122also shows a wire 1130 disposed within catheter 1105. As described ingreater detail below, wire 1130, in one embodiment, may be coupled atone end to a cutting element (not shown) disposed near the distalportion 1120, and to a handle (e.g., handle 1115) at the opposite end.When a heart chord (e.g., mitral valve chordae) is positioned acrossnotch 1122, a cutting element (e.g., a blade) may be moved from one sideof the notch to the opposite side of the notch, in a direction of theelongated catheter, to slice through or cut the chord. Control mechanism1112 disposed near proximal portion 1110 may have one or more handles(e.g., handles 1114, 1115, 1116) to provide operability to medicaldevice 1100, including steerability of distal portion 1120 and theactuation of the cutting element back and forth across notch 1122.

FIG. 2 illustrates another side view of a medical device 200 that may beused to cut a heart chord percutaneously. An enlarged view of distalportion 220 shows notch 222 formed within catheter 205. Notch 222 has afirst proximal side 260 and a second distal side 262 along alongitudinal length of catheter 205. A lumen 235 is also formed withincatheter 205 extending down to the distal portion 220. A cutting element240 may be disposed within lumen 235. In one embodiment, cutting element240 may include a blade portion 242 that may be partially covered byblade support 245. Blade support 245 may provide rigidity and mechanicalsupport to blade portion 242 when slicing through a heart chord and mayalso protect heart tissue from the back side of the blade. In may beappreciated by one of skill in the art that cutting element 240 may onlyinclude blade portion 242, without blade support 245. In one embodiment,cutting element 240 may be made of a uniform material, including varioustypes of metal that may be contemplated for a blade (e.g., stainlesssteel). Alternatively, blade support 245 and blade portion 242 may bemade of different materials. For example, blade portion 242 may be madeof stainless steel, and blade support may be made of a polymer.

In one embodiment, cutting element 240 may be positioned near the distalside 262 of notch 222 (as shown in FIG. 2) such that no portion ofcutting element (e.g., blade portion 242 or blade support 245) extendsout into notch 222. Blade support 245 may be coupled to a wire 230 thatextends to proximal portion 210 and that is coupled to control mechanism212. Distal portion 220 also shows a steering tendon 270 extending to apoint near proximal side of notch 222. Steering tendon 270 may becoupled to an inner surface of catheter 205 within lumen 235. Steeringtendon 270 enables distal portion 220 to be steered and flexed to adesired orientation. In one embodiment, steering tendon 270 may becontrolled by a handle disposed on a control mechanism (e.g., controlmechanism 212). Distal portion 220 may have multiple steering tendonsdisposed therein. Steering tendons are well known in the art;accordingly, a detailed description is not provided. An optionalguidewire lumen 250 may also be formed within catheter 205 which may beused to advance a guidewire 252 therethrough. As described in greaterdetail below, guidewire 252 may be used to percutaneously advance distalportion 220 of device 200 to a region in the patient's heart.

An enlarged view of proximal portion 210 shows catheter 205 coupled tocontrol mechanism 212. Control mechanism includes handles 214, 215, 216.In one embodiment, handle 214 may be coupled to steering tendon 270,handle 216 may be coupled to a second steering tendon 272, and handle215 may be coupled to wire 230. Handles 214, 215, 216 may be movedforwards and backwards within slots formed on control mechanism 212. Forexample, handle 215 may be moved forwards and backwards to move cuttingelement 240 across notch 222. In an alternative embodiment, handles 214,216 that control steering tendons 270, 272, respectively may be knobsthat rotate to produce a steering effect of tendons 270, 272.

FIG. 2A illustrates a cross-sectional view of device 200 taken alongline A-A near distal portion 220. This view of device 200 near proximalside 260 of notch 222 has lumen 235 formed within catheter 205. Lumen235 has a hemi-spherical shape with steering tendons 270, 272 attachedto an inner surface of catheter 205 within lumen 235. Wire 230 sits in agroove 232 formed within lumen 235. Groove 232 may be sized to securewire 230 therein, and to prevent wire 230 from freeing itself andreleasing into lumen 235. Catheter 205 also has a guidewire lumen 250for advancing a guidewire 252 therein. FIG. 2B illustrates across-sectional view of device 200 taken along line B-B of FIG. 2Abetween a proximal side 260 and a distal side 262 of notch 222. Thispart of device 200 does not have lumen 235 formed by catheter 205.Groove 232 which secures wire 230, as well as guidewire lumen 250 havingguidewire 252 disposed therein, extend through this part of device 200.FIG. 2C illustrates a cross-sectional view of device 200 taken alongline C-C of FIG. 2A near distal side 262 of notch 222. Catheter 205forms lumen 235 with cutting element 240 positioned therein. In oneembodiment, lumen 235 distal to notch 222 may be narrowed to formslightly wider than groove 232. The shape and size of lumen 235 distalto notch 222 prevent cutting element 240 from tilting when positionedwithin the distal portion 220 of catheter 205. Alternatively, lumen 235near distal to notch 222 may be formed substantially similar to the viewshown in FIG. 2C. Blade support 245 partially covers blade portion 242of cutting element 240, with blade support 245 sitting in groove 232.The nearly closed shape of groove 232 enables cutting element to remainupright. As described in greater detail below, groove 232 may havealternative designs to support cutting element 240. Guidewire lumen 250having guidewire 252 also extends through this part of device 200.

FIGS. 3A-3D illustrate one exemplary embodiment of the mechanical actionof a cutting element disposed within a medical device (e.g., device 200described above). FIG. 3A illustrates a side view of a distal portion300 of catheter 305 with a heart chord 390 (e.g., a mitral valvechordae) positioned within a notch 322 formed within catheter 305. Notch322 has a first proximal side 360 and a second distal side 362 withchord 390 positioned between them. Cutting element 340 is disposedwithin catheter 305 and positioned near distal side 362 of notch 322.Cutting element 340 includes a blade portion 342 partially covered byblade support 345. In one embodiment, blade portion 342 may be slightlycurved, although as described in greater detail below, alternativedesigns for blade portion 342 may be used. Blade support 345 may extendfrom the distal side 362 to the proximal side 360 of notch 322, andcoupled to wire 330. In an alternative embodiment, blade support 345 maybe relatively short, and not extend a length from a distal side 362 to aproximal side 360 of notch 322. By pulling on wire 330 (e.g., with ahandle on a control mechanism 212), cutting element 340 may be retractedfrom a position near distal side 362 of notch 322 to the proximal side360. In doing so, blade portion 342 slices through chord 390, asillustrated by FIG. 3B. Cutting element 340 may then be returned neardistal side 362 of notch 322 to perform another cutting procedure (e.g.,to cut another chord).

FIG. 3C illustrates a top view of distal portion 300 of catheter 305.The view shown may be that of cutting element 340 positioned near adistal side 362 of notch 322 illustrated in FIG. 3A. A groove 332extends within catheter 305 of distal portion 300. In one embodiment,groove 332 serves as track for cutting element 340 to movelongitudinally within catheter 305. As discussed above, groove 332 maybe shaped to secure blade support 345 and wire 330. As shown in FIG. 3D,cutting element 340, with blade portion 342, is retracted linearlywithin catheter 305 along groove 332 to slice through chord 390.

As described above, embodiments of a medical device described herein mayhave steering capabilities to advance a cutting element disposed withina distal portion of a catheter to a target region in a patient's heart.FIGS. 4A-4B illustrate one embodiment of steering tendons disposedwithin the catheter to provide steering capabilities. FIG. 4A shows atop view of a distal portion 400 of catheter 405. Tendons 470, 472extend within an inner surface of catheter 405 from a point proximal tonotch 422 back to control mechanism 412 that may be disposed near aproximal portion of catheter 405. A cutting element 440 is positioneddistal to notch 422 and may be moved in the manner described above,relative to notch 422 to cut a chord. Tendon 470 may be coupled tohandle 413 and tendon 472 may be coupled to handle 416. Handle 413 mayinclude lever 415 slidable along slot 414, and handle 416 may includelever 418 slidable along slot 417. In one embodiment, sliding lever 415along slot 414 may pull tendon 470 to steer distal portion 400 ofcatheter 405 in a particular direction. Analogously, sliding lever 418along slot 417 may pull tendon 472 to steer distal portion 400 ofcatheter 405 in a direction opposite to that steered by tendon 470. FIG.4B shows one embodiment of a range of motion of distal portion 400 thatmay achieved by pulling on tendons 470, 472 with handles 413, 416disposed on control mechanism 412. Control mechanism 408 may alsoinclude a knob 408 that enables catheter 405 to be rotated about alongitudinal axis. The ability to rotate distal portion 400, along withthe steering abilities provided by steering tendons 470, 472 enables anoperator to position a heart chord within notch 422.

FIGS. 5A-5D illustrate alternative embodiments of steering tendonsdisposed within a catheter 405. As illustrated by these cross-sectionalviews, the number of tendons and the position of the tendons withincatheter 405 may be variable, and not limited to the two tendons (470,472) described above. Tendons (e.g., tendons 470, 472, 474, 476) may bedisposed in different orientations with respect to groove 432 formedwithin catheter 405. For example, the use of four tendons as shown byFIG. 5D may provide the maximum amount of steerability to catheter 405.In one embodiment, each tendon shown in FIG. 5D may be coupled toindividual control handles on control mechanism 412.

FIGS. 6A-6C illustrate side views of alternative embodiments for acutting element that may be disposed within embodiments of a medicaldevice described herein (e.g., cutting element 340 described withrespect to FIG. 3 or cutting element 240 of FIG. 2). For example, FIG.6A illustrates cutting element 600A with blade support 645A forming aslot with a cutting edge of blade portion 642A extending from a topportion of the slot to a bottom portion of the slot, but substantiallydisposed within the slot. FIG. 6B illustrates cutting element 600B withblade support 645B forming a smaller slot compared to the slot formed bythe embodiment of FIG. 6A. Cutting edge of blade portion 642B extendsfrom an outer end of a top portion of blade support 645B to an inner endof bottom portion of blade support 645B. FIG. 6C illustrates yet anotherembodiment of cutting element 600C with blade support 645C forming aslot analogous to that formed by blade support 645B of FIG. 6B. Bladeportion 642C forms two cutting edges extending along a top portion and abottom portion of blade support 645C.

FIGS. 7A-7C illustrate side views of alternative embodiments for notchdesigns that may be formed within a distal portion of a medical deviceto cut heart chords (e.g., notch 322 described with respect to FIG. 3).For example, FIG. 7A shows a notch 722A having a substantially squaredesign formed within catheter 705A. FIG. 7B shows a notch 722B thatopens to a larger size within catheter 705B. FIG. 7C shows yet anotherembodiment of notch 722C formed within catheter 705C in which one sideof notch 722C may be slightly curved and an opposite side may besubstantially straight. In one embodiment, the notches described hereinmay have a depth of about 0.5 mm to 1.5 mm and a length of about 1 mm to4 mm.

FIGS. 8A-8D illustrate cross sectional views of alternative embodimentsfor a groove that may be formed within embodiments of a medical devicedescribed herein (e.g., groove 232 described with respect to FIG. 2 andcross sectional view FIG. 2C). In one embodiment, the groove formedwithin a catheter provides support to keep the cutting element uprightand prevent tilting while the cutting element moves within the catheter.The shape of the groove may also serve to prevent the wire and/orcutting element from popping out during movement. The groove alsoprovides a track so that the cutting element may maintain a linear pathwhen pulled by the wire disposed within the groove. In one embodiment, across-sectional design of the wire may determine the correspondingdesign of the groove. For example, FIG. 8A shows wire 830A having asubstantially spherical design and groove 832A having a hemisphericaldesign to accommodate the design of wire 830A. Cutting element 840A isshown coupled to wire 830A. FIG. 8B shows another embodiment of a groovedesign for a substantially spherical wire 830B in which groove 832B hasa substantially straight portion that opens up to substantiallyspherical groove. A portion of cutting element 840B may sit deeper ingroove 832B compared to cutting element 840A. FIG. 8C shows anotherembodiment of a groove design in which wire 830C has a substantiallyelliptical shape with groove 832C also having a substantially ellipticalshape. FIG. 8D shows yet another embodiment of a groove design in whichwire 830D may have a substantially trapezoidal shape with groove 832Dhaving a similar design to accommodate wire 830D. The embodiments for agroove shown in FIGS. 8B-8D may be especially effective in preventing awire from popping of the groove during movement of the cutting element.Moreover, because a portion of cutting element is embedded within thegrooves in these embodiments, rotation of the cutting element may beeffectively prevented.

FIGS. 9A-9B illustrate an alternative embodiment for preventing rotationof a cutting element disposed within a catheter. In this embodiment, alongitudinal length of the notch is made shorter than the cuttingelement such that a portion of the cutting element is always containedwithin the catheter. Additionally, a width of the catheter may be justlarge enough to contain the cutting element and prevent its rotation.FIG. 9A shows a side view of catheter 900 having a cutting element 940overlapping a size of notch 922. FIG. 9B shows a top view of catheter900 with cutting element 940 spanning across a longitudinal length ofnotch 922. Because cutting element 940 is longer than notch 922, thecutting element 940 tends not to rotate when exposed in notch 922.

FIGS. 10A-10D illustrate one exemplary method for cutting a mitral valvechordae tendineae percutaneously. In one embodiment, the medical deviceused to cut the chordae may be device 200 described above with respectto FIG. 2. FIG. 10A illustrates a simplified, cross-sectional view of aleft side of a heart including aortic arch 202, left atrium 204 and leftventricle 206. A chordae tendineae 208 attaches a mitral valve leaflet207 with a tissue portion of left ventricle 206. For the purposes ofdescribing a method to cut a target chordae, only chordae 208 is shown,although it may be understood that more than one chordae may be cut withdevice 200. A distal portion of catheter 205 has been percutaneouslyadvanced into the left ventricle 206. In one embodiment, a guidewire(not shown) may be initially advanced into the left ventricle byinserting the guidewire into, for example, the femoral artery, down theaortic arch 202, and into left ventricle 206. Catheter 205 may be loadedand tracked over the guidewire to be positioned near chordae 208 (e.g.,through guidewire lumen 250 formed within catheter 205). In alternativeembodiments, catheter 205 may be any of the catheter types used in theart, including but not limited to “rapid exchange” (RX) catheters,“over-the-wire” (OTW) catheters, or a “tip RX” catheters. If a guidewireis utilized, the guidewire may be removed after the distal portion ofcatheter 205 has entered the left ventricle. Various imaging techniquesknown in the art may also be used to locate chordae 208. For example,echo imaging, infrared illumination, x-ray, and magnetic resonanceimaging methods may be utilized. These imaging techniques are known inthe art; accordingly, a detailed description is not provided.

Catheter 205 extends back to a proximal portion 210 disposed outside ofa patient. Catheter 205 may be coupled to a control mechanism 212 whichincludes control handles 214, 215, 216. The control handles may be used,in one embodiment, to steer and/or rotate the distal portion of catheter205, in particular, to position notch 222 around chordae 208. Forexample, handles 214, 216 may be manipulated to steer and/or rotatecatheter 205 (e.g., with steering tendons 270, 272 described above) toposition chordae 208 within notch 222 as illustrated by FIG. 10B. Withnotch 222 positioned around chordae 208, handle 215 disposed on controlmechanism may be pulled (in the direction of the arrow as indicated inFIG. 10C) to retract a cutting element (e.g., cutting element 240)disposed within catheter 205 from a position on a distal side to aproximal side of notch 222. In one embodiment, the action of the cuttingelement may be that described above with respect to cutting element 340of FIGS. 3A-3B. FIG. 10D shows chordae 208 having been cut into twoportions. Catheter 205 may then be tracked back up the aortic arch 202and out of the patient or alternatively, notch 222 may be positionedover another target chordae to be severed. For example, handles 214, 216may be used to steer catheter 205 to another target chordae, and handle215 used to reposition the cutting element near a distal side of notch222.

In one embodiment, a heart chord cutting method discussed herein may becombined with another approach for treating a defective mitral valve(e.g., mitral valve regurgitation). This additional approach includesapplying a support member in the coronary sinus near the mitral valveregion or applying a support member on the mitral valve itself, such ason the mitral valve annulus, or applying a first support member in thecoronary sinus and applying a second support member on the mitral valveannulus. In this embodiment, a general technique would include cuttingpercutaneously one or more heart chords and also applying percutaneouslya support member on the mitral valve or applying a support member in thecoronary sinus. The combination of percutaneous chord cutting with thisadditional percutaneous approach should provide improved mitral valvefunctionality. These additional approaches are described in severalco-pending U.S. patent applications which are hereby incorporated byreference, these applications being: (1) Apparatus and Methods for HeartValve Repair, by inventors Gregory M. Hyde, Mark Juravic, Stephanie ASzobota, and Brad D. Bisson, filed Nov. 15, 2002, attorney docket no.005618.P3591; (2) Heart Valve Catheter, by inventor Gregory M. Hyde,filed Nov. 15, 2002, attorney docket no. 005618.P3456; (3) ValveAdaptation Assist Device, by inventors William E. Webler, James D.Breeding, Brad D. Bisson, Firas Mourtada, Gregory M. Hyde, Stephanie A.Szobota, Gabriel Asongwe, and Jeffrey T. Ellis, filed Nov. 15, 2002,attorney docket no. 005618.P3665; (4) Valve Annulus ConstrictionApparatus and Method, by inventors Peter L. Callas and Richard Saunders,filed Nov. 15, 2002, attorney docket no. 005618.P3560; (5) Methods forHeart Valve Repair, by inventors William E. Webler, Gregory M. Hyde,Christopher Feezor and Daniel L. Cox, filed Nov. 15, 2002, attorneydocket no. 005618.P3635; and (6) Apparatus and Methods for Heart ValveRepair, filed Oct. 15, 2002, attorney docket no. 005618.P3575.

A kit (e.g., a kit of multiple catheters with instructions) maybe usedto perform the combination of the percutaneous chord cutting withanother percutaneous approach (e.g., such as applying percutaneously amitral valve annulus). For example, a first catheter, such as catheter205 described above, may be combined with a kit with a second catheterdesigned to apply a member percutaneously, such as a support annulus tothe mitral valve region or a stent-like structure in the coronary sinusnear the mitral valve. The second catheter may be used to deploy asupport annulus around the mitral valve annulus to reshape the mitralvalve, or a set of joined clips which grasp mitral valve leaflets, or astent or ring or stent-like structure in the coronary sinus to reshapethe mitral valve.

For example, FIGS. 12A-12B illustrate one embodiment of performing acombination procedure of percutaneous mitral valve chordae cutting withpercutaneous placement of a support annulus on the mitral valve annulus.FIG. 12A shows a first catheter 205 having a cutting element disposednear a distal end and positioned near chordae 208 in left ventricle 206.A second catheter 290 has also been advanced percutaneously into theleft atrium 204 (e.g., transeptally) and positioned over mitral valveannulus 295. A support member 292 is disposed near a distal portion ofsecond catheter 290. FIG. 12B shows chordae 280 having been cut with acutting element (e.g., cutting element 240 described above), as well assupport member 290 having been attached to mitral valve annulus 295.Upon completion of each percutaneous procedure, first catheter 205 maybe removed back up the aortic arch 202 and second catheter 290 may beremoved back across the septum.

In the foregoing specification, a medical device has been described withreference to specific exemplary embodiments thereof. For example, themedical device may be used to treat heart chords other than the chordaetendineae of the mitral valve. It will, however, be evident that variousmodifications and changes may be made thereto without departing from thebroader spirit and scope of the medical device as set forth in theappended claims. The specification and figures are, accordingly, to beregarded in an illustrative rather than a restrictive sense.

1. A kit for treating a heart valve, the kit comprising: a firstcatheter having a cutting element, said first catheter having a size andshape to be percutaneously advanced and positioned relative to a heartvalve chord, said cutting element for cutting through said heart valvechord; a second catheter having a support member which is released fromsaid second catheter, said support member being deployed percutaneouslyby said second catheter to at least one of a region of a mitral valve ora region of a coronary sinus adjacent to said mitral valve.
 2. The kitof claim 1, further comprising instructions for using said kit.
 3. Thekit of claim 1, wherein said cutting element is disposed near a notch ina distal portion of said first catheter and wherein said support memberreshapes a mitral valve annulus.
 4. A method for cutting a heart valvechord, the method comprising: advancing a cutting element disposed witha catheter to said heart valve chord percutaneously; positioning saidheart valve chord relative to said cutting element; cutting through saidheart valve chord with said cutting element.
 5. The method of claim 4,wherein cutting further comprises operating a control mechanism coupledto said cutting element.
 6. The method of claim 5, wherein positioningfurther comprises steering said catheter with said control mechanism. 7.The method of claim 4, wherein advancing further comprises placing saidcatheter in a left ventricle of a patient's heart.
 8. The method ofclaim 7, wherein positioning further comprises placing a mitral valvechordae relative to said cutting element.
 9. A method for treating aheart valve, the method comprising: advancing a cutting element disposedwith a catheter to a heart valve chord percutaneously; positioning saidheart valve chord relative to said cutting element; cutting through saidheart valve chord with said cutting element; deploying percutaneously asupport member to at least one of a region of a mitral valve or a regionof a coronary sinus adjacent to said mitral valve.
 10. The method ofclaim 9, wherein said cutting element is disposed near a notch in adistal portion of said catheter and wherein said support member reshapesa mitral valve annulus.
 11. The method of claim 10, wherein saiddeploying comprises advancing said support element with a secondcatheter.
 12. A method for cutting a heart valve chord, the methodcomprising: advancing a cutting element disposed within a catheter tosaid heart valve chord percutaneously, said catheter having a notchformed therein; positioning said heart valve chord within said notch;actuating said cutting element across said notch to slice through saidheart valve chord.
 13. The method of claim 12, wherein actuating furthercomprises retracting said cutting element from a first position distalto said notch to a second position proximal to said notch.
 14. Themethod of claim 13, wherein actuating further comprises operating acontrol mechanism coupled to said cutting element.
 15. The method ofclaim 14, wherein positioning further comprises steering said catheterwith said control mechanism.
 16. The method of claim 12, whereinadvancing further comprises placing said catheter in a left ventricle ofa patient's heart.
 17. The method of claim 16, wherein positioningfurther comprises placing a mitral valve chordae within said notch.